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Discussion Starter #1
Alright guys and gals, been working on my fuel tank for two days now with no success.

So long story short, I broke one of the bolts that holds the fuel pump down off the tank this last winter. The fuel pump is held down by 8 bolts, and I am not sure if because of the loss of one of these bolts it is causing my car to run weird. So I am trying to reattach the bolt to the tank without having it rewelded on.

I have attempted to use silver bearing solder, but where it sticks to the stainless steel bolt, it will not stick to then tank. I have tried using JB Weld, but it did not work either, held it, but not very strongly, it broke off as I was trying to fit the ring back in. I tried to drill a hole in the gas tank so that I could either run a screw through the tank from up above to hold the fuel pump down, or thread a bolt up from the bottom to act as a similar set up to what I already have. But after 2.5 hours and two drill bits, I have only managed a small divit in the top of the tank where the bolt is supposed to go. So right now, I have NO desire of pulling the tank and having it welded, but I do want that bolt back on there to properly secure the fuel pump in place.

Anyone have any insight on how to repair this, or what I need to repair it, other than removing the tank and having it welded...as most welders will still not want to touch it since it is a fuel tank.

Thanks.
 

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Discussion Starter #4
For the bits, I am using just your standard $8 a set from the local hardware store, Titanium coated.

In terms of the small pieces of metal, I created a "Catch" system below where I am drilling using tape, as I have found that the tank is NOT magnetic. Which is what REALLY confuses me, as I thought all steels were magnetic. So to help with the excess material, that is where the tape "bed below is used to catch the excess material.
 

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Gamera The Atomic Turtle
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there was a great fuel tank in the parts for sale section too. Cheap.
 

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Discussion Starter #9
I don't have a check engine light, just have a HUGE idle issue. Fast bounce rev from 1500 - 2500 rpms. I installed a VF2 kit, and I double checked ALL my piping to make sure it was nice and clean, but so far, no luck.

I was going to seal it after drilling the hole, but at this point in time, I talked to a couple of welders and got some good ideas on what to do. Going to drain the last of the fuel (1/2 gallon), then let it sit for a couple of days, then clean out what is left over, and then see if I can get a mobile welder in there to just spot weld the two pieces together. If not, I should be able to get either a brazing torch or (need to find a hot enough soldering iron) in there to heat that part of the tank up to do a Silver Solder job. I didn't realize that BOTH surfaces had to be up to temp to actually get the silver solder to stick. Where I can get the bolt nice and hot, I am not able to get the tank surface that hot.

I just needed a night to sleep on it, and breathe again. While I am waiting for the tank air out enough, I plan on doing a boost pressure leak on the motor to see where my leaks (if any exist) really are. So that is where I am at now.
 

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Discussion Starter #11
so talked to a couple of welding guys today about the best way to approach the situation with the tank. I have absolutely no desire to pull the tank, so here is what I plan on doing.

Tomorrow I will remove the last 1/2 gallon of fuel out of the tank, and then leave the tank open and exposed to just air out. I am going to give it about 4 days. During this time I am going to boost test the car's s/c system to see if I can track down that stupid vaccum leak.

Then, I plan on washing the tank out with Berryman's cleaner, so that I can get anymore of the remaining gas fumes out of there that may still exist. Then next week, I plan on calling a couple of welders that have a mobile unit to see if anyone is willing to tack weld the bolt to the tank (I figure it should take them no more than 5 minutes to do this). If they are willing then SWEET, if not, then I will be tackling the issue with a brazing torch and silver solder again.

I will shove a vaccum in the fill hole (turn it on the vent out the side), leave the tank's fuel pump hole plugged as best I can to restrict air flow through the tank (try to remove as much oxygen as I can), and then hopefully (without blowing up), heat up the tank with the brazen torch, heat up the bolt with the brazen torch, and then silver solder the two pieces together.

I have about a minute to get the silver solder in place and then put the bolt on top before it all cools to much to melt the solder, so it will give me enough time. Just hope I don't pop before that.

IF that doesn't work, and the car and I are in one piece still, then I plan on drilling a hold through the tank, threading a bolt through the tank from the underside and JB welding it on the top to seal it, and aide in keeping the bolt in place, and putting it all back together.

So fingers crossed, we will see. :) Thoughts on this plan?
 

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I would NOT use a vacuum. One of my friends burned his garage and house down doing exactly that. Sparks from the vac motor ignited some fumes and BOOM!

I would also pull the tank if you plan on welding it.

BUT if I were doing this repair I think I'd just get some gas tank sealer and put a bead around the fitting vs what you are doing. Or pull the fitting out, drill through and thread it for a bolt that goes in from the inside. Use rags/grease to keep shavings from going in the tank. Also can use a stick with tape on the end to get any that fell in.

I think you are making a big project out of what could be an easy repair., though without seeing it, maybe I'm wrong.
I will shove a vaccum in the fill hole (turn it on the vent out the side), leave the tank's fuel pump hole plugged as best I can to restrict air flow through the tank (try to remove as much oxygen as I can), and then hopefully (without blowing up), heat up the tank with the brazen torch, heat up the bolt with the brazen torch, and then silver solder the two pieces together.
 

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Puff Daddy
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You're gonna die.
:panic: Not what I'd want to hear from a physician rotfl

Pretty sure you have a vacuum leak somewhere else. I'd leave the tank alone until you can be certain it's not something easier in the intake tract. Check everything including the o-rings on the injectors.
 

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I also vote on a leak in your intake manifold.

Missiong one bolt shouldn't effect your tank seal, unless there was a hole through the metal, but I personally would forget about welding on or adding the bolt back on, and I would make sure the tank is sealed. If the gap is small, you can use some Hylomar Universal Blue sealant along with the normal tank o-ring and locking hardware to make sure it is sealed. It is like a syrup that will fill in the gaps if any.
 

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purveyor of lightness
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You're gonna die.
Holy crap - that's the funniest thing I've read all day.

Seriously dude pull the tank - I'm the biggest wimp when it comes to gasoline and fumes and stuff and it took me only about two hours to drop the tank three years ago when I upgraded it to the ProAlloy.

I *did* however sweat the entire time thinking I was defusing an atomic bomb. :D
 

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Discussion Starter #19
LOL,

Thanks for the encouraging words Roaddad...it is much appreciated.

I had a good friend who has welded quite a few gas tanks tell me a trick of his. And we were all pondering whether the missing of one bolt would seriously make the tank leak in anyway, so the idea of welding/brazing the bolt back on is still up for debate, but the new trick I learned today really has me thinking it wouldn't be hard at all.

Either way, long story short...I will let you know in a couple of days what I think/plan on doing with it. I plan on starting with a boost pressure leak system tomorrow to see if I can find the leak that way first.

FYI: I have already changed all the o-rings on the injectors, so they are all new. I did disassemble my fuel pump, it looks to be in the proper arrangement in terms of putting it together, and I have checked/double checked all my clamping points at on the tubes to make sure they were properly placed in regards to the flair on the tubes and the t-clamp locations.

So the only thing left to look at:

Leak at the intake manifold (which will drive me insane as this will be the third one I would have to install).
Leak at the S/C (which will also drive me insane as this will be the only place I could not check yet)
Bad throttle position sensor.
Or Bad MAF sensor.

So tomorrow will be a boost pressure test to see if I can track down the leak(s) that way.

Sorry to disappoint Roaddad...but I do not playing on blowing up "Just yet." :D
 

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Late to the thread, but...

I welded an MGTD tank years back. Filled it nearly full of water and welded away.

The water is not easy to get out of the tank but maybe easier than the gas fumes.

Good Luck.
 
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